Cellulose derivative compositions



I Patented Aug. 4, 1936" UNITED STATES 2,049,565 cELLoLosE DERIVATIVE comrosmous Harold S. Bolt,.Wilmington, DeL, assignor to E. I. du Pont de Nemours a Company, Wilmington, Del., a corporation of Delaware No Drawing. Application April 23, 1935,

Serial No. 17,771

18 Claims. ol. 106-37) This invention relates to new compositions of matter, more particularly to esters of tetrahydronaphthalenedicarboxylic acids, and still more particularly to coating, plastic, and the like com- .5 positions containing cellulose derivatives and these esters.

In copending application Serial No. 751,581, filed November 5, 1934, there is disclosed the preparation of certain estersof tetrahydronaphthalenedicarboxylic acids.

Thisinvention has as an object the preparation of compositions containing cellulose derivatives plasticized by esters of tetrahydronaphthalenedicarboxylic acids or other polycyclic aromatic- 5 alicyclic dicarboxylic acids.

These objects are accomplished by the following invention wherein a cellulose derivative composition is plasticized by means of an ester of a tetrahydronaphthalenedicarboxylic acid or other 20 polycyclic aromatic-alicyclic dicarboxylic acid.

Esters of tetrahydronaphthalenedicarboxylic acids may be made in several ways. Thus, the corresponding ester of a dihydronaphthalenedicarboxylic acid may be hydrogenated to the tetra- 25 hydronaphthalenedicarboxylic acid ester. Es-

ters may also be made by reacting a tetrahy- Example 1.The dimethyl ester of tetrahydronaphthalenedicarbozylic acid The preparation of the dimethyl ester of dihyo dronap'hthalenedicarboxylic acid is described in .copending application. Serial No. 743,843. The

' dimethyl. esters thus obtained are hydrogenated by subjecting them to a hydrogen pressure of 1,000 to 1,500 lbs/sq. in. in the presence of an 5 activated nickel catalyst at a temperature of .150 to 180 C. The resulting hydrogenated product isa substantially colorless oily liquid having a boiling range of' 130 to 195 Chair approximately 2 mm. pressure, a specific gravity of 1.16, a refractive index of 1.5196, and a molecularweight of about 248. It is soluble in all portions in methanol, ethanol, benzene, trichloroethane and cyclohexane. During the hydrogenation it is found that approximately one mol of hydrogen 55 is absorbed per mol of ester used. It is also found that whereas one mol of the original ester will react with bromine to form an addition compound,-the hydrogenated ester is substantially unreactive toward bromine at.0 C. in the dark.

Example 2.--The didodecyl 'ester of tetrahydronaphthalenedicarborylic acids The didodecyl esters of dihydronaphthalenedicarboxylic acids are prepared by ester interchange between the methylestersianddodecyl alcohol as described in copending application, Serial No. 743,843. The didodecyl esters thus prepared are hydrogenated under the conditions of Example '1 except that about one-third part by vollmie of cyclohexane is added as a solvent. The product obtained 'is a colorless oil which has such a low vapor pressure that it cannot be distilled even in vacuo, below decomposition temperature. It

is soluble in absolute alcohol and somewhat soluble in cyclohexane. Its refractive index is 1.488 2 and it does not react with bromine in the dark at 0 C.

Example 3.-Dinaphthenyl tetrahydronaphthalenedicarborylates litharge, 20 g. of carbon added and the product A mixture containing 124 g. of dimethyl ester of tetrahydronaphthalenedicarboxylicacids, 311 g. abietyl alcohol (hydroxyl No. 180, prepared by sodium reduction of ethyl abietate), 200 g. 1101- uene, 5 g. litharge is refluxed for 18 hours at 145- 198 C. while the methanol produced is continually removed as the toluol-methanol binary at the top of the fractionating column. The product is filtered hot, 5 g. of carbon added and refluxed for I 2 hours and again filtered to remove colloidal litharge. The product is then refined in a manner similar to that described in Example 3.

The esters prepared as above described vary in physical properties from substantially colorless oily liquids to very viscous liquids which probably should be crystalline. They are extremely high boiling and are quite compatible with cellulose derivatives.

The methyl ester in particular is very satisfactorily compatible with cellulose acetate as are also the methyl glycollate and the methoxyethyl esters, and even more compatible with cellulose esters of other organic acids, cellulose nitrate, and cellulose ethers. The esters of higher alcohols such as butyl are compatible in more limited amounts. With cellulose nitrate and cellulose ethers the esters are in general compatible in large amounts. These esters are readily soluble in all of the common organic solvents and are miscible with other materials commonly used as plasticizers. They are in general, the not perhaps in all cases, compatible with the various natural and synthetic resins such as polyvinyl acetate, polymerized methyl methacrylate, polystyrene, polyhydrlc alcohol polybasic acid resins, phenolaldehyde resins, modified phenol-aldehyde resins v such as Amberol and Beckacite, ether resins, and

q manymaturalresins such asdamar.

Monohydric m'coliols in generafmay be used to esterify tetrahydronaphthalenedicarboxylic acids or to esterify the dihydronaphthalenedicarboxylic acids which are then hydrogenated a's esters to esters of the tetrahydronaphthalenedicarboxylic acids. Aliphatic alcohols from methyl to octadecyl including the branched chain primary and secondary alcohols containing six to eight or even more carbon atoms obtained by the catalytic hydrogenation of carbon oxides at elevated temperatures and pressures, aromatic alcohols such as benzyl alcoholand substituted benzyl alcohols, alicyclic alcohols such as cyclohexanol, substituted cyclohexanols and cyclohexyl substi-' tuted alkanols as well as the naphthenyl alcohols rivative coating compositions, which utility is exemplifled in the following examples:

. Example 5 Parts Cellulose nitrate 12 Damar Y 3 Dibutyl tetrahydronaphthalenedicarboxylate 4 Castor oil 2.6 Solvent 166 Example 6 Parts Cellulose isobutyrate 10 Diethyl tetrahydronaphthalenedicarboxylate 3 Solvent 100 Example 7 Parts Cellulose acetate 12 The above lacquers give films which dry in a few minutes and which are tough, flexible and very durable. By the term solven in the above examples is meant a suitable mixture of esters,

alcohols and hydrocarbons such as is already well 35 known to those skilled in the art.

These esters are also of value as plasticizers in plastic compositions such as those exemplified below:

Example 11 40 Parts Cellulose acetate 100 Dimethyl tetrahydronaphthalenedicarboxylatev 75 Example 12 Parts Cellulose nitrate 100 D i b u t y l tetrahydronaphthalenedicarboxylnfe 5O Pigment (including color) 200 504 Example 13 Parts Ethyl cellulose 100 Carbomethoxymethyl methyl tetrahydro naphthalenedicarboxylate 15 Example 14 Parts Cellulose laurate 100 'Dibutyl tetrahydronaphthalenedicarboxyl- The above plastic compositions may be prepared with or without the usual volatile solvent,

for example, alcohol for the cellulose nitrate w compositions, acetone for the cellulose acetate compositions, and 'toluol alcohol mixture for the cellulose ether compositions. Other cellulose derivatives such as cellulose propionate, cellulosebutyrate, cellulose acetobutyrate', benzyl cellulose, glycol cellulose; cellulose glycollic acid, etc., may be substituted for the cellulose derivatives given in the examples. Any part of the plasti-' cizer in the above examples may be replaced by other plasticizers of the group included within "the scope of the present invention, or in part by one or more of the plasticizers hitherto known ,to the art including triacetin, camphor, dibutyl phthalate, tricresyl phosphate, dimethoxyethyi f capable of considerable variation. Furthermore,

while the invention has been disclosed in the .terms of esters of tetrahydronaphthalenedi carboxylic-acids, esters of polycyclic aromatic-- alicyclic dicarboxylic acids, i. e., esters containing an aromatic ring and a fully hydrogenated aromatic ring on-which hydroaromatic rings are situated two carboxyl groupsare generally of use in cellulose derivative compositions, and the invention therefore includes such compositions within its scope. These esters include the esters of the .hexahydrodiphenyl, tetrahydroanthracene', and

36 tetrahydrophenanthrenedicarboxylie acids. These esters may be prepared by the hydro genation of the esters of dihydrodiphenyl-, dihydroanthracene-, and dihydrophenanthrenedicarboxylic acids. The esters -may be prepared from the sodium addition compounds of the corresponding aromatic hydrocarbons by the method set forth in copending application Serial No. 638,524.

The esters of the acids containing a fully yd ovgenated hydroaromatic ring are even more satisfactory for general use as'plasticizers than the corresponding dihydronaphthalene derivatives because of their increased color stability and stability towards oxidizing agents.

Cellulose derivative compositions of the present invention may be used in-the preparation of lacquers and vamishes for coating .metal and wood, dopes for coating fabrics, lacquers for-coat ing. regenerated cellulose sheeting, plastic. compositions useful in the preparation of toiletware,

novelties, sheeting, rods, tubing, safety glass interlayers. and lacquers for coating wire screen.- and in the preparation of thin transparent sheets for wrapping purposes. Among the examples given above are those illustrating iytype of composition suitable for each of these uses. I

The high boiling water resistant plasticizers of the-present invention are highly compatible with "cellulose derivatives and may also be usedv withnatural and synthetic resins and. oils.. Because of the low. vapor pressure of the plasticizer the cellulose derivative plastics containing them are permanently, flexible and have gooddurability,

and for example, are more advantageousthan corresponding phthalates.

Theabove description and ples are intended to beillustrative only. Anymodiflcation {of orvariation therefrom which conforms to the Spirit of the invention is intended to in-' eluded withinthe scope of the claims."

"I claim:

1. A new composition of matter comprising cellulose acetate, and as a plasticizer therefor, a

dimethyl tetrahydrona'phthalenedicarbonylate.

2. A new composition of matter comprising a dialkyl tetrahydronaphthalenedicarboxylate.

cellulose derivative, and as a plasticizer therefor,

cellulose ester, and as a plasticizer therefor, a dimethyl tetrahydronaphthalenedicarboxylate.'

3. A new composition of matter comprising a cellulose derivative, and as a plasticizer therefor,

a dimethyl tetrahydronaphthalenedicarboxylate. 5

4. A new composition of matter comprising cellulose nitrate, and as a plasticizer therefor, a didodecyl tetrahydrpnaphth lenedicarboxylate.

5. A new. composition 0 matter comprising a cellulose ester, and as a p icizer therefor, a didodecyl tetrahydronaphthalenedicarboxylate.

6. A new composition of matter comprising a cellulose derivative, and as a plasticizer therefor, a didodecyl tetrahydronaphthalenedicarboxylate.

7. A new composition of matter comprising cellulose nitrate, and as a'plast icizer therefor, a neutral ester of a tetrahydro aphthalenedicarboxylic acid with the mixture 0 alcohols obtainable by the carboxyl reduction of the fatty acids of coconut oil. a I

8. 'A new composition of matter comprising a cellulose ester, and as a plasticizer therefor, a neutral ester of a tetrahydronaphthalenedicarboxylic acid with the mixture of. alcohols obtainable by the carboxyl reduction of the fatty acids 25 of coconut oil.

h 9. A new composition of matter comprising a cellulose derivative, and as a plasticizer therefor,

' a neutral ester of a tetrahydronaphthalenedicar boxylic acid with the mixture of alcohols obtainable by the carboxyl reduction of the fatty acids of coconut oil. I I Y 10. A new composition of matter comprising cellulose nitrate, and as a plasticizer therefor, a' 5 -3 11. A new composition of matter comprising a cellulose ester, and as a plasticizer therefor, a

' dialkyl tetrahydronaphthalenedicarboxylate.

12. A new composition of matter comprising a 40 a dialkyl tetrahydronaphthalenedicarboxylate.

13. A cellulose derivative composition containing, as a plasticizer therefor, a neutralesterpf a tctrahydronaphthalenedicarboxylic acid.

14. A cellulose derivative composition containing, as a plasticizer therefor, an ester of a tetrahydronaphthalenedicarboxylic acid.

, 15. A cellulose derivative composition containing, as a plasticizertherefor, aneutral ester of a polycyclic dicarboxylic acid containing. at least one aromatic ring, and a fully hydrogenated aromatic ring on which hydroaromatic ring are situated two carboxyl groups. p

- 16. A cellulose derivative compo ition containing, as a plasticizer therefor; an esterof a polycyclic dicarboxylic acid containing at least one aromatic ring, and a fully hydro enated aromatic ring on which hydroaromatic ring-are situated twocarboxyl 8 ml. a

1'7. A cellulose derivative composition containing as aplasticizer therefor, a neutral ester of a polycyclic dicarbox'y'lic acid of the class consisting of tetrahydronaphthalenedicarboxylic,

hexahydrodiphenyldicarboxylic, tetrahydroanthracenedicarboxylic and tetrahydrophenanboxylic acids.

. HAROLD s. HOLT. 

